In the tire manufacturing industry, certain tire parts are formed starting from continuous strip of elastomeric material. Transverse cuts are made in the strips either by hand or by means of a power driven blade inclined in relation to the surface supporting the uncut strip. Successive strips are cut off the ends of a continuous strip of a particular material for subsequent joining on a drum in a tire building process. The hand cuts usually result in a non-uniform cut difficult to satisfactorily join in a splice and is time consuming.
During each cutting operation the power driven blade induces relatively severe cutting stress in the strip on account of the inclined position of the blade in relation to the strip surface. At normal output rates, the stress, which depends somewhat on the type of blade, cutting speed, and type of material being cut, is usually severe enough to deform the strip by wrinkling the strip at the cutting line, generally immediately upstream from the blade. Such wrinkling of the strip results in inaccurate and undulated cuts. Attempts have been made to reduce these cutting stresses by the use of rotary blades. However, at the output rates permitted on current tire manufacturing machines the sole employment of rotary blades have proven insufficient for preventing local deformation and crumpling or wrinkling of the strip during cutting. Many of these deformable strips used in the building of tires are multi-components of materials increasing further the difficulty of achieving a satisfactory cut because the rubber of one component is smeared into adjacent components during the cutting of the strip.
Another problem with the cutting of such strips is that the resultant beveled edges are contaminated with the material being cut from the strip and by lubricants used with the cutting operation required to cool the cutting blade and to provide a smooth cut joint especially when the strip is comprised of several different materials.
This contamination, either resulting from the cut material or from the lubricant residue, requires subsequent cleaning and if not cleaned, results in an unsatisfactory joint or splice when the beveled ends are joined. Such contamination, if allowed, adversely affects assembly adhesion of the beveled ends and the cosmetic appearance, resulting in a substandard product. Also this need of cleaning the severed ends of the strip prior to joining adds another manufacturing operation, thereby increasing the costs of the final product produced thereby.
Heretofore strips have been cut with rotary knives to provide a better cut than a linear knife blade and have also used lubricants to cool the blade and to increase the cutting ability of the blade. Furthermore, it has been known that to reduce the crumpling or wrinkling of the strip being cut to press or retain the strip tightly against a surface adjacent the cut line by mechanical hold-down means, vacuum, or the like.